1. Field Of The Invention
The subject invention generally pertains to swap body containers, and more specifically, to a device that restrains a parked swap body container.
2. Description Of Related Art
A swap body is typically a large freight container having four retractable legs. The legs are usually retracted while the swap body is in transit on the bed of a truck, trailer, ship, or rail car. When parked at a truck loading dock, the legs are typically extended to support the container upon a driveway with the floor of the container generally aligned flush to the floor of the loading dock. This allows a forklift to drive into the container for loading or unloading, yet allows the truck that delivered the container to leave.
While the legs provide a vertical/columnar support for the weight of the container and its contents (and material handling equipment), the legs are not designed to resist substantial horizontal forces. Substantial horizontal forces, however, can be exerted on the legs. For example, if the forklift inside the container was to suddenly stop by applying the brakes or striking cargo, the horizontal reaction force would be transmitted to the container""s legs. Since a forklift can weigh thousands of pounds, and given the relative instability of the legs to resist horizontal movement, it is possible that an abrupt stop or collision could cause the container to move horizontally away from the dock, opening up a potentially hazardous gap between the container and the dock. Further, such horizontal movement could place a torque or bending force on one or all of the legs, causing them to buckle, or fold up, or (in a worst-case scenario) to collapse altogether. Such an accident might seriously harm the forklift operator, others nearby, the cargo or surrounding structure.
One means for restraining a truck trailer atop a railroad car is disclosed in U.S. Pat. No. 4,718,800. The device includes a support plate (item 18) for engaging a kingpin that extends out from underneath the bottom of the trailer. The support plate is rather wide, possibly to accommodate a slot having a wide lead-in for catching a kingpin that may be disposed substantially off-center or difficult to see, and thus, possibly difficult to align to the slot. Moreover, with the kingpin being underneath the container, it may be difficult to visually confirm that the pin is fully engaging the plate. Of course, such a device also relies upon the presence of a kingpin to properly operate.
In order to minimize undesirable horizontal movement of a swap body, there is provided a restraint for a parked swap body container that includes a face stop that can be positioned to a restraining position or a release position relative to the front face of the container. In the restraining position, the face stop is adapted to engage a front face of the container to limit the extent to which the parked container can move away from an edge of a truck loading dock. In the release position, the face stop allows movement of the container, for example to allow a truck to remove the container from the loading dock.
Such a restraint helps keep a swap body container from slipping too far away from the edge of the dock, thereby possibly avoiding creating a hazardous gap between the container and the edge of the loading dock and the related undesirable forces on the legs that could lead to their failure.
In some embodiments, the restraint is able to be removed to a location that is completely out of the way for delivering and removing a swap body from a loading dock, or possibly for facilitating snow removal of the loading dock""s driveway.
Some embodiments also include a fine adjustment which is advantageous in further limiting the extent to which a parked swap body container could otherwise move away from the loading dock.